1. Field of the Invention
The invention relates to a semiconductor device or element having at least two zones of different conductivity type therein, each of which are respectively provided with an electrode, such as for an integrated circuit.
2. Prior Art
Our copending U.S. Ser. No. 587,996, filed June 18, 1975 assigned to the instant assignee and which is incorporated herein by reference, discloses and claims a method of producing a doped zone of a select conductivity type in a semiconductor member whereby an initially undoped polycrystalline semiconductor layer is deposited on a surface of the zone to be doped and a dopant producing the select conductivity type in such zone is diffused through the polycrystalline semiconductor layer into the semiconductor member.
Such a method differs from the so-called "DOPOS" technique which uses doped polycrystalline silicon as a dopant source in producing an emitter (see M. Takagi et al, "Improvement of Shallow Base Transistor Technology By Using A Doped Poly-Silicon Diffusion Source", Proceedings of the 4th Conference on Solid State Devices, Tokyo, 1972, pages 101-109). It should be noted that the use of undoped poly-silicon which is subsequently doped yields transistors and the like with better properties (for example, higher current amplification, lower inner path resistance, lower noise, etc.).